Android http download file and save to local or SD card

To save the file to the SD card, be sure to know the path of the SD card and get the SD card path:

Environment.getexternalstoragedirectory ()

In addition, before saving to determine whether the SD card is installed, and can read and write:

// determine if the sdcard exists and can read and write if (Environment.getexternalstoragestate (). Equals (environment.media_mounted)) {                    Service.savetosdcard ( filename,filecontent);                    Toast.maketext (Getapplicationcontext (), R. string 1 ). Show ();                } Else {                    toast.maketext (Getapplicationcontext (), R. string 1 ). Show ();                }

Instance

1. Download the text files and download large-capacity files such as mp3

2. Code writing

Configuration in Androidmainfest.xml

Mainly to resolve network permissions and write SDcard permissions

<?xml version="1.0"encoding="Utf-8"? ><manifest xmlns:android="http://schemas.android.com/apk/res/android" Package="com.jingling.practice.downloadtest"> <uses-permission android:name="Android.permission.INTERNET"/> <uses-permission android:name="Android.permission.WRITE_EXTERNAL_STORAGE"/> <Application Android:allowbackup="true"Android:icon="@drawable/ic_launcher"Android:label="@string/app_name"Android:theme="@style/apptheme"> <Activity Android:name=". Mainactivity"Android:label="@string/app_name"> <intent-filter> <action android:name="Android.intent.action.MAIN"/> <category android:name="Android.intent.category.LAUNCHER"/> </intent-filter> </activity> </application></manifest>

Package Util;import Android.util.log;import java.io.bufferedreader;import java.io.file;import Java.io.ioexception;import Java.io.inputstream;import Java.io.inputstreamreader;import java.net.HttpURLConnection ; Import Java.net.URL;/** * Created by Spring on 2015/11/7. * Download Tool class*/ Public classHttpdownloader {PrivateURL url =NULL; PrivateFinal String TAG ="TAG"; /** * Read text file * @param urlstr URL Path * @return text message * Download the file according to the URL, provided the content in this file is text, * 1. Create a URL Object * 2. Create an HTTP connection via the URL object * 3. Get InputStream * 4. Get data from InputStream*/     Publicstring Download (string urlstr) {StringBuffer sb=NewStringBuffer (); String Line=NULL; BufferedReader BufferedReader=NULL; Try{URL=NewURL (URLSTR); //Create an HTTP connectionHttpURLConnection Urlconn =(HttpURLConnection) url.openconnection (); //reading data using IO streamBufferedReader =NewBufferedReader (NewInputStreamReader (Urlconn.getinputstream ()));  while(line = Bufferedreader.readline ())! =NULL) {sb.append (line); }        } Catch(IOException e) {e.printstacktrace (); }        finally {            Try{bufferedreader.close (); } Catch(IOException e) {e.printstacktrace (); }} log.e ("TAG","Download TXT file"); LOG.E ("TAG", sb.tostring ()); returnsb.tostring (); }    /** * Read Any file * return-1, on behalf of the download failed. Returns 0, which represents success. Returns 1 means the file already exists * * @param urlstr * @param path * @param fileName * @return*/     Public intdownlaodfile (String urlstr, String path, String fileName) {InputStream input=NULL; Try{fileutil Fileutil=NewFileutil (); if(Fileutil.isfileexist (Path +fileName)) {                return 1; } Else{input=Getinputstearmformurl (URLSTR); File Resultfile=Fileutil.write2sdfrominput (path,filename,input); if(Resultfile = =NULL)                    return-1; }        } Catch(IOException e) {e.printstacktrace (); return-1; }        finally {            Try{input.close (); } Catch(IOException e) {e.printstacktrace (); }        }        return  0; }     PublicInputStream Getinputstearmformurl (String urlstr) throws IOException {URL=NewURL (URLSTR); HttpURLConnection Urlconn=(HttpURLConnection) url.openconnection (); InputStream input=Urlconn.getinputstream (); returninput; }}

Fileutil.java

Package Util;import Android.os.environment;import java.io.file;import java.io.fileoutputstream;import Java.io.ioexception;import Java.io.inputstream;import Java.io.OutputStream;/** * Created by Spring on 2015/11/7.*/ Public classFileutil {PrivateString Sdpath;  PublicFileutil () {} PublicString Getsdpath () {returnSdpath; }     PublicFileutil (String sdpath) {//get a directory of external storage devices (/sdcard)Sdpath = environment.getexternalstoragedirectory () +"/" ; }    /** * Create file on SD card * @param fileName * @return * @throws java.io.IOException*/     Publicfile Createsdfile (String fileName) throws IOException {file file=NewFile (Sdpath +fileName);        File.createnewfile (); returnfile; }    /** * Create directory on SD card * @param dirName directory name * @return file directory*/     Publicfile Createdir (String dirName) {file dir=NewFile (Sdpath +dirName);        Dir.mkdir (); returndir; }    /** * Determine if the file exists * @param fileName * @return*/     Publicboolean isfileexist (String fileName) {File file=NewFile (Sdpath +fileName); returnfile.exists (); }     Publicfile Write2sdfrominput (String path,string filename,inputstream input) {file file=NULL; OutputStream Output=NULL; Try{createdir (path); File=createsdfile (path +fileName); Output=Newfileoutputstream (file); byte[] buffer =New byte[4*1024x768];  while(Input.read (buffer)! =-1) {output.write (buffer);            Output.flush (); }        } Catch(IOException e) {e.printstacktrace (); }        finally {            Try{output.close (); } Catch(IOException e) {e.printstacktrace (); }        }        returnfile; }}

3.MainActivity

Package Com.jingling.practice.downloadtest;import Android.app.activity;import android.os.bundle;import Android.view.view;import android.widget.button;import util. Httpdownloader; Public classMainactivity extends Activity {Httpdownloader downloader; PrivateButton Btn_downfile; PrivateButton Btn_downmp3; @Overrideprotected voidonCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);        Setcontentview (R.layout.activity_main); Btn_downfile= (Button) This. Findviewbyid (R.id.button); Btn_downmp3= (Button) This. Findviewbyid (R.id.button2); Btn_downfile.setonclicklistener (NewView.onclicklistener () {@Override Public voidOnClick (View v) {Downloader=NewHttpdownloader (); String Urlstr="Http://172.17.54.91:8080/download/down.txt";            Downloader.download (URLSTR);        }        }); Btn_downmp3.setonclicklistener (NewView.onclicklistener () {@Override Public voidOnClick (View v) {String urlstr="Http://172.17.54.91:8080/download/1.mp3"; String Path="file"; String FileName="2.mp3"; Httpdownloader Httpdownloader=NewHttpdownloader ();            Httpdownloader.downlaodfile (Urlstr,path,filename);    }        }); }}

Android http download file and save to local or SD card